1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
/*
* Copyright 2012 Sebastian Annies, Hamburg
*
* Licensed under the Apache License, Version 2.0 (the License);
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an AS IS BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.googlecode.mp4parser.authoring.tracks;
import com.coremedia.iso.boxes.*;
import com.googlecode.mp4parser.authoring.Track;
import com.googlecode.mp4parser.authoring.TrackMetaData;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import java.util.logging.Logger;
/**
* Changes the timescale of a track by wrapping the track.
*/
public class ChangeTimeScaleTrack implements Track {
private static final Logger LOG = Logger.getLogger(ChangeTimeScaleTrack.class.getName());
Track source;
List<CompositionTimeToSample.Entry> ctts;
List<TimeToSampleBox.Entry> tts;
long timeScale;
/**
* Changes the time scale of the source track to the target time scale and makes sure
* that any rounding errors that may have summed are corrected exactly before the syncSamples.
*
* @param source the source track
* @param targetTimeScale the resulting time scale of this track.
* @param syncSamples at these sync points where rounding error are corrected.
*/
public ChangeTimeScaleTrack(Track source, long targetTimeScale, long[] syncSamples) {
this.source = source;
this.timeScale = targetTimeScale;
double timeScaleFactor = (double) targetTimeScale / source.getTrackMetaData().getTimescale();
ctts = adjustCtts(source.getCompositionTimeEntries(), timeScaleFactor);
tts = adjustTts(source.getDecodingTimeEntries(), timeScaleFactor, syncSamples, getTimes(source, syncSamples, targetTimeScale));
}
private static long[] getTimes(Track track, long[] syncSamples, long targetTimeScale) {
long[] syncSampleTimes = new long[syncSamples.length];
Queue<TimeToSampleBox.Entry> timeQueue = new LinkedList<TimeToSampleBox.Entry>(track.getDecodingTimeEntries());
int currentSample = 1; // first syncsample is 1
long currentDuration = 0;
long currentDelta = 0;
int currentSyncSampleIndex = 0;
long left = 0;
while (currentSample <= syncSamples[syncSamples.length - 1]) {
if (currentSample++ == syncSamples[currentSyncSampleIndex]) {
syncSampleTimes[currentSyncSampleIndex++] = (currentDuration * targetTimeScale) / track.getTrackMetaData().getTimescale();
}
if (left-- == 0) {
TimeToSampleBox.Entry entry = timeQueue.poll();
left = entry.getCount() - 1;
currentDelta = entry.getDelta();
}
currentDuration += currentDelta;
}
return syncSampleTimes;
}
public SampleDescriptionBox getSampleDescriptionBox() {
return source.getSampleDescriptionBox();
}
public List<TimeToSampleBox.Entry> getDecodingTimeEntries() {
return tts;
}
public List<CompositionTimeToSample.Entry> getCompositionTimeEntries() {
return ctts;
}
public long[] getSyncSamples() {
return source.getSyncSamples();
}
public List<SampleDependencyTypeBox.Entry> getSampleDependencies() {
return source.getSampleDependencies();
}
public TrackMetaData getTrackMetaData() {
TrackMetaData trackMetaData = (TrackMetaData) source.getTrackMetaData().clone();
trackMetaData.setTimescale(timeScale);
return trackMetaData;
}
public String getHandler() {
return source.getHandler();
}
public boolean isEnabled() {
return source.isEnabled();
}
public boolean isInMovie() {
return source.isInMovie();
}
public boolean isInPreview() {
return source.isInPreview();
}
public boolean isInPoster() {
return source.isInPoster();
}
public List<ByteBuffer> getSamples() {
return source.getSamples();
}
/**
* Adjusting the composition times is easy. Just scale it by the factor - that's it. There is no rounding
* error summing up.
*
* @param source
* @param timeScaleFactor
* @return
*/
static List<CompositionTimeToSample.Entry> adjustCtts(List<CompositionTimeToSample.Entry> source, double timeScaleFactor) {
if (source != null) {
List<CompositionTimeToSample.Entry> entries2 = new ArrayList<CompositionTimeToSample.Entry>(source.size());
for (CompositionTimeToSample.Entry entry : source) {
entries2.add(new CompositionTimeToSample.Entry(entry.getCount(), (int) Math.round(timeScaleFactor * entry.getOffset())));
}
return entries2;
} else {
return null;
}
}
static List<TimeToSampleBox.Entry> adjustTts(List<TimeToSampleBox.Entry> source, double timeScaleFactor, long[] syncSample, long[] syncSampleTimes) {
long[] sourceArray = TimeToSampleBox.blowupTimeToSamples(source);
long summedDurations = 0;
LinkedList<TimeToSampleBox.Entry> entries2 = new LinkedList<TimeToSampleBox.Entry>();
for (int i = 1; i <= sourceArray.length; i++) {
long duration = sourceArray[i - 1];
long x = Math.round(timeScaleFactor * duration);
TimeToSampleBox.Entry last = entries2.peekLast();
int ssIndex;
if ((ssIndex = Arrays.binarySearch(syncSample, i + 1)) >= 0) {
// we are at the sample before sync point
if (syncSampleTimes[ssIndex] != summedDurations) {
long correction = syncSampleTimes[ssIndex] - (summedDurations + x);
LOG.finest(String.format("Sample %d %d / %d - correct by %d", i, summedDurations, syncSampleTimes[ssIndex], correction));
x += correction;
}
}
summedDurations += x;
if (last == null) {
entries2.add(new TimeToSampleBox.Entry(1, x));
} else if (last.getDelta() != x) {
entries2.add(new TimeToSampleBox.Entry(1, x));
} else {
last.setCount(last.getCount() + 1);
}
}
return entries2;
}
public Box getMediaHeaderBox() {
return source.getMediaHeaderBox();
}
public SubSampleInformationBox getSubsampleInformationBox() {
return source.getSubsampleInformationBox();
}
@Override
public String toString() {
return "ChangeTimeScaleTrack{" +
"source=" + source +
'}';
}
}
|
